Compound engine.



No. 755,508. O PATENTED MAR. 22, 1904. P. LINCOLN, DEGD.

A. e. LINOOLN, ADMINISTRATRIX. COMPOUND ENGINE.

APPLICATION FILED FEB. 13I 1902.

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r I M affoznal'qa PATENTED MAR. 22, 1904.

I. LINCOLN, DEGDQ A; G. LINCOLN, ADMINIBTRATEIX.

COMPOUND ENGINE.

APPLICATION FILED FEB. 13, 1902.

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UNITED STATES FREDERICK LINCOLN, OF WARREN, MASSACHUSETTS; ALICE G.LINCOLN Patented March 22, 1904.

PATENT OFFICE.

I COIVIPOUND ENGINE.

srncrrrcn'rroiv forming part of Letters Patent No. 755,508, dated March22,1904.

Application filed February 13, 1902- Serial No. 93,951. (No model.)

To all whom it may concern:

Be it known that I, FREDERICK LINCOLN, a citizen of the United States,residing at Warren, in the county of Worcester and State ofMassachusetts, have invented a new and useful Compound Engine, of whichthe following is a specification.

This invention relates generally to steam-engines, and particularly tocompound engines, it being understood that the principle of theinvention is applicable to triple-expansion engines and also toexpansion-engines of higher multiples.

The object of the invention is to prevent back pressure, common incompound engines as now constructed; and incidental to the removal ofthe back pressure the invention also has for its object to increase theefficiency of the ordinary vacuum-pump now used in connection withcompound expansive engines.

With these objects in view the invention consists in the novel featuresof construction and combination, all of which will be fully describedhereinafter and pointed out in the claims.

In the drawings forming part of this specification, Figure 1 is a sideelevation of an engine constructed in accordance with my inone set ofcylinders and illustrating the relative position of the various portsand valves during the downstroke of the high-pressurecylinder piston A,intermediate-cylinder piston B, and upstrokeof the low-pressurecylinderpiston C. 3 is a similar view 1 illustrating the relative position ofthe ports and valves during the upstroke of the saidhigh-presSure-cylinder piston, piston B, and upstroke of piston C I Inconstructing an engine of the kind shown in the drawings I employ threecylinders A, B, and C. The cylinders A and B are integral and arrangedtandem-like, the cylinder C being preferably arranged at one side of thecylinder B. The cylinder A is a high-pressure cylinder, and thecylinders B and C are respectively low-pressure, secondary, and tertiarycylinders; My invention relates especially to the manner of feeding thesteam from,

one of these cylinders to the other. A piston A Works in the cylinder A,and a piston B in the cylinder B, both pistons being mounted on thepiston-rod B In the cylinder C is a piston C, secured at the inner endof a pistonrod C The outer ends of both these pistonrods are secured tosuitable crank-rods arranged at an angle of one hundred and eightydegrees to each other.

Before describing the construction of the valve passages and ports indetail it may be first stated that I employ the Corliss valve, thoughslide-valves could be used, and that any desired mechanism may be usedfor actuating these valves, and any suitable governor may,

be used with the engine, the valve-actuating mechanism not being a partof this invention.

Fresh live steam is admitted into the cylinder A only, and for thispurpose the port A is provided on one side and midway the ends of thecylinder. This inlet A has direct communication only with thevalve-casing A which in turn communicates with the valvecasing A*through a grated valve-seat A, and the casing A has communication withthe cylinder A through an inletport A, communicating with the upperinterior part of the cylinder. Adjacent the lower end of the cylinder Aand on the same side as the former mentioned valve-casing is arranged avalve-casing A whichcommunicates with the interior of the cylinderthrough the inletport A, with the casing A through a passage A, with anexhaust-port A and with the cylinder B through means to be describedhereinafter.

Valve-casing B is arranged adjacent the upper end of the cylinder B anda casing B adjacent the lower end of said cylinder. A passage B connectsthe valve-casings A and B and a passage B is a continuation of thepassage B and leads to the valve-casing B. The casing B hascommunication with the interior of the cylinder B by means of aninletport B and with an exhaust-port, to which is attached avacuum-pump, by the passage B The casing B communicates with theinterior of the cylinder B through a passage B and also communicateswith an exhaust-passage B, which is also connected to the. vacuumpump.

A passage B leads from the juncture of the passages B and B to thevalve-casing C from which a port C leads into the cylinder C. Adjacentthe opposite or lower end of the cylinder C is a valve-casing C", havingcommunication with the interior of the cylinder through the passage Ccommunication with the exhaust and vacuum pump through the passage C andwith the valve-casing by means of the passage C Having now mentioned indetail all the valve-casings and their connecting passage-ways, I willstate that a two-way valve D is arranged in the valvecasing A and acut-off valve E in the casing A. Valves similar in construction to thevalve E are arranged in the other casings: the valve F in the casing A,G in the casing B H in the casing B, I in the casing C and K in thecasing G.

The operation of my engine is as follows: When the engine starts, thevalves are assumed to be in the position shown in Fig. 2, and it willalso be remembered that the exhaust-passages are connected to avacuum-pump and that there is a vacuum below the pistons A and B andabove the piston C. Live steam is admitted through the inlet-port A byway of the casing A A and port A", and the pistons on the rod B commencetraveling in the direction of the arrows in Fig. 2. When aboutone-fourth of the stroke has been made, steam is cut off, and the steamworks expansively during the remainder of the stroke. At the end of thestroke the valves are shifted to the position shown in Fig. 2. It willbe borne in mind that up to this time there has been no steam incylinders B and C. With the shifting of the valves steam passes from thecylinder A, from above the piston A, through passages A A B B, throughthe valve-casing B and port B to the under side of the piston B and alsothrough the passage B to the valve-casing C and thence tothe upper partof the cylinder C through the port C. The pistons B and 0 thereforecommence to move in opposite directions, and it will be remembered thaton this movement the piston B has steam below it and a vacuum above andthat the opposite is true of the piston C. The piston A, however, alsooriginally had a vacuum below it, and in order to destroy this and tomore easily enable the-pistons B and C to force the piston A back to itsoriginal position the passages and valves are so arranged that when thevalves are shifted to the position shown in Fig. 3 there will becommunication through the valve-casing A and port A between the passageA and the lower part of the cylinder A. The course of the steam has nowbeen traced, and it has been noted that the steam expands first abovethe the cylinder A. The casing A is now in communication with theexhaust and the vacuumpump, and the same is true of the casing B, sothat no steam will remain below the pistons A and B to cushion them onthis second downward stroke. All of the steam which had been admitted tothe cylinder A on the first downward stroke has not, however, beenexhausted, for as the valves shift to their original position apassage-way is formed through the passages C, casing 0 passage B casingB and port B to the upper part of the cylinder B, which on the previousdownward stroke had no steam in it, and also through the passage Ccasing C and port C establishing a balance on the two sides of thepiston C, as had been previously formed in the cylinder A. It will benoted, therefore, that on the second stroke while live steam is workingagainst the upper side of the piston A and a balance is being formed andmaintained in the cylinder C what may be termed original steam isworking in the upper portion of the cylinder B and is finally exhaustedthrough the passage B at the end of the second downstroke of the pistonsA and B.

The engine has now been fairly started, steam having been admitted oneach side of each cylinder, and it is thought that the further operationof the engine will be clearly understood.

It will be further borne in mind that the aim and object of thisconstruction is to relieve the' pistons of any back pressure, which isdone in each case at the proper time by either balancing the pressure oneach side of a piston or by connecting the exhaust end of the cylinderwith a vacuum-pump. At no time during the operation above described isany piston moving against a back pressure.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. The combination with a high-pressure cylinder having inlet andexhaust ports, of a low-pressure cylinder arranged in tandem with thehigh-pressure cylinder, a valve-controlled passage being arrangedbetween the two cylinders, the low-pressure cylinder having anexhaust-port adjacent the end opposite the high-pressure cylinder, acommon piston-rod, pistons on said rod, one piston being arranged ineach cylinder, a second low-pressure cylinder arranged adjacent thefirst low-pressure cylinder and having an exhaust-port adjacent one endand a valve-controlled inlet-port adjacent the opposite end incommunication with the passage between the two first-mentionedcylinders, a piston-rod in the second low-pressure cylinder and a pistonon said rod.

2. An engine of the kind described comprising three cylinders, two ofsaid cylinders being arranged tandem, and having suitable pistons andpiston-rods, a steam-pipe connected to one of said cylinders, avacuum-pump having connection with each cylinder, valves adapted toadmit steam successively through each of the three cylinders from thesteampipe mentioned, and means for automatically actuating the saidvalves.

3. A compound engine comprising a highpressure cylinder and twolow-pressure cylinders, a piston-rod common to the high-pressurecylinder and one of the low-pressure cylinders, a piston in eachcylinder, a piston and piston-rod in the other low-pressure cylinder,means for creating a vacuum below the pistons on the common piston-rodand above the piston in the other low pressure cylinder, means foradmitting live steam' to the highpressure cylinder only, means forcutting the supply of said steam ofi? when a quarter-stroke has beenmade, and means for passing a portion of said steam successively intoand through the two low-pressure cylinders, substantially as and for thepurpose described.

4. A compound engine, comprising a highpressure cylinder, having asteam-inlet, a twoway valve, inlet and exhaust ports and inlet andexhaust cut-off valves, a passage connecting the inlet and exhaustports, an exhaustpassage leading from the exhaust-port, a secondarycylinder having inlet and exhaust ports, and inlet and cut-ofi valvesadjacent thereto, a passage connecting the inlet and exhaust ports, anexhaust-port leading from the inlet-port and the exhaust-passageleading-

